/************************************************************************
                                                                     
   Xceed Ultimate ListBox for Silverlight                                                                                                                                            
   Copyright (C) 2010 Xceed Software Inc.    
                                                                     
   This program is provided to you under the terms of the GNU General Public  
   License version 2 as published by the Free Software Foundation. 
        
   This program is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY, without even the implied warranty of 
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License along 
   with this program, if not, write to the Free Software Foundation, Inc., 
   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

   This program can be provided to you by Xceed Software Inc. under a
   proprietary commercial license agreement for use in non-Open Source
   projects. Visit Xceed.com to find the commercial edition of 
   Xceed Ultimate ListBox for Silverlight.                                    
                                                                      
 **********************************************************************/

using System;
using System.Diagnostics;
using System.Windows;
using Xceed.Silverlight.ListBox.Utils;
using Xceed.Silverlight.Utils;
using Xceed.Silverlight.DragDrop;

namespace Xceed.Silverlight.ListBox
{
  public abstract class ContainerConfigurationsBase : DependencyObject, IWeakEventListener
  {
    #region CONSTRUCTORS

    private static ListBoxItemConfiguration DefaultListBoxItemConfiguration;
    private static ListBoxGroupHeaderConfiguration DefaultListBoxGroupHeaderConfiguration;

    static ContainerConfigurationsBase()
    {
      ContainerConfigurationsBase.DefaultListBoxItemConfiguration = new ListBoxItemConfiguration();
      ContainerConfigurationsBase.DefaultListBoxGroupHeaderConfiguration = new ListBoxGroupHeaderConfiguration();

      Debug.Assert( ( ContainerConfigurationsBase.DefaultListBoxItemConfiguration.ContentTemplate == null ) && ( ContainerConfigurationsBase.DefaultListBoxItemConfiguration.ContainerStyle == null ) );
      Debug.Assert( ( ContainerConfigurationsBase.DefaultListBoxGroupHeaderConfiguration.ContentTemplate == null ) && ( ContainerConfigurationsBase.DefaultListBoxGroupHeaderConfiguration.ContainerStyle == null ) );
    }

    public ContainerConfigurationsBase()
    {
      // Always instanciate a DraggedContainerConfiguration as default value.
      // We don't want to affect the DP default value to avoid a static reference
      // shared by more than one ContainerConfigurations
      this.DraggedElementConfiguration = new DraggedElementConfiguration();
    }

    #endregion CONSTRUCTORS

    #region DraggedContainerConfiguration Property

    public static readonly DependencyProperty DraggedElementConfigurationProperty = DependencyProperty.Register(
      "DraggedElementConfiguration",
      typeof( DraggedElementConfiguration ),
      typeof( ContainerConfigurationsBase ),
      new PropertyMetadata(
        null,
        new PropertyChangedCallback( ContainerConfigurationsBase.OnDraggedElementConfigurationChanged ) ) );

    public DraggedElementConfiguration DraggedElementConfiguration
    {
      get
      {
        return ( DraggedElementConfiguration )this.GetValue( ContainerConfigurationsBase.DraggedElementConfigurationProperty );
      }
      set
      {
        this.SetValue( ContainerConfigurationsBase.DraggedElementConfigurationProperty, value );
      }
    }

    private static void OnDraggedElementConfigurationChanged( DependencyObject sender, DependencyPropertyChangedEventArgs e )
    {
      ContainerConfigurationsBase containerConfiguration = ( ContainerConfigurationsBase )sender;

      DraggedElementConfiguration oldDraggedElementConfiguration = e.OldValue as DraggedElementConfiguration;
      DraggedElementConfiguration newDraggedElementConfiguration = e.NewValue as DraggedElementConfiguration;

      containerConfiguration.Invalidate();
    }

    #endregion

    #region ListBoxItemConfiguration Property

    public static readonly DependencyProperty ListBoxItemConfigurationProperty = DependencyProperty.Register(
       "ListBoxItemConfiguration",
       typeof( ListBoxItemConfiguration ),
       typeof( ContainerConfigurationsBase ),
       new PropertyMetadata( null, ContainerConfigurationsBase.OnListBoxItemConfigurationChanged ) );

    public ListBoxItemConfiguration ListBoxItemConfiguration
    {
      get
      {
        return ( ListBoxItemConfiguration )this.GetValue( ContainerConfigurationsBase.ListBoxItemConfigurationProperty );
      }
      set
      {
        this.SetValue( ContainerConfigurationsBase.ListBoxItemConfigurationProperty, value );
      }
    }

    private static void OnListBoxItemConfigurationChanged( DependencyObject sender, DependencyPropertyChangedEventArgs e )
    {
      ContainerConfigurationsBase containerConfiguration = ( ContainerConfigurationsBase )sender;

      ListBoxItemConfiguration oldListBoxItemConfiguration = e.OldValue as ListBoxItemConfiguration;
      ListBoxItemConfiguration newListBoxItemConfiguration = e.NewValue as ListBoxItemConfiguration;

      if( oldListBoxItemConfiguration != null )
      {
        ContentTemplateChangedManager.RemoveListener( oldListBoxItemConfiguration, containerConfiguration );
        ItemContainerStyleChangedManager.RemoveListener( oldListBoxItemConfiguration, containerConfiguration );
      }

      if( newListBoxItemConfiguration != null )
      {
        ContentTemplateChangedManager.AddListener( newListBoxItemConfiguration, containerConfiguration );
        ItemContainerStyleChangedManager.AddListener( newListBoxItemConfiguration, containerConfiguration );
      }

      containerConfiguration.Invalidate();
    }

    #endregion ItemConfiguration Property

    #region ListBoxGroupHeaderConfiguration Property

    public static readonly DependencyProperty ListBoxGroupHeaderConfigurationProperty = DependencyProperty.Register(
       "ListBoxGroupHeaderConfiguration",
       typeof( ListBoxGroupHeaderConfiguration ),
       typeof( ContainerConfigurationsBase ),
       new PropertyMetadata( null, ContainerConfigurationsBase.OnListBoxGroupHeaderConfigurationChanged ) );

    public ListBoxGroupHeaderConfiguration ListBoxGroupHeaderConfiguration
    {
      get
      {
        return ( ListBoxGroupHeaderConfiguration )this.GetValue( ContainerConfigurationsBase.ListBoxGroupHeaderConfigurationProperty );
      }
      set
      {
        this.SetValue( ContainerConfigurationsBase.ListBoxGroupHeaderConfigurationProperty, value );
      }
    }

    private static void OnListBoxGroupHeaderConfigurationChanged( DependencyObject sender, DependencyPropertyChangedEventArgs e )
    {
      ContainerConfigurationsBase containerConfigurations = ( ContainerConfigurationsBase )sender;

      ListBoxGroupHeaderConfiguration oldListBoxGroupHeaderConfiguration = e.OldValue as ListBoxGroupHeaderConfiguration;
      ListBoxGroupHeaderConfiguration newListBoxGroupHeaderConfiguration = e.NewValue as ListBoxGroupHeaderConfiguration;

      if( oldListBoxGroupHeaderConfiguration != null )
      {
        ContentTemplateChangedManager.RemoveListener( oldListBoxGroupHeaderConfiguration, containerConfigurations );
        ItemContainerStyleChangedManager.RemoveListener( oldListBoxGroupHeaderConfiguration, containerConfigurations );
      }

      if( newListBoxGroupHeaderConfiguration != null )
      {
        ContentTemplateChangedManager.AddListener( newListBoxGroupHeaderConfiguration, containerConfigurations );
        ItemContainerStyleChangedManager.AddListener( newListBoxGroupHeaderConfiguration, containerConfigurations );
      }

      containerConfigurations.Invalidate();
    }

    #endregion ListBoxGroupHeaderConfiguration Property

    #region Public Methods

    public void Invalidate()
    {
      // Invalidate everything.
      this.Invalidate( ConfigurationType.All );
    }

    #endregion Public Methods

    #region Internal Methods

    internal void Invalidate( ConfigurationType configurationType )
    {
      if( this.ContainerConfigurationsInvalidated != null )
      {
        this.ContainerConfigurationsInvalidated( this, new ConfigurationChangedEventArgs( configurationType ) );
      }
    }

    internal ListBoxContainerConfigurationBase GetContainerConfiguration( ConfigurationType configurationType )
    {
      if( configurationType == ConfigurationType.All )
        throw new ArgumentException( "Any not a valid ConfigurationType value", "configurationType" );
      ListBoxContainerConfigurationBase containerConfiguration = this.GetContainerConfigurationCore( configurationType );

      // We never want to return a null configuration as there must always be an
      // active configuration for a given container type.
      // Use the default configurations instead.
      if( containerConfiguration == null )
      {
        if( configurationType == ConfigurationType.Item )
        {
          containerConfiguration = ContainerConfigurationsBase.DefaultListBoxItemConfiguration;
        }
        else if( configurationType == ConfigurationType.GroupHeader )
        {
          containerConfiguration = ContainerConfigurationsBase.DefaultListBoxGroupHeaderConfiguration;
        }
      }

      return containerConfiguration;
    }

    internal ListBoxContainerConfigurationBase GetContainerConfigurationCore( ConfigurationType configurationType )
    {
      ListBoxContainerConfigurationBase containerConfiguration = null;

      if( configurationType == ConfigurationType.Item )
      {
        containerConfiguration = this.ListBoxItemConfiguration;
      }
      else if( configurationType == ConfigurationType.GroupHeader )
      {
        containerConfiguration = this.ListBoxGroupHeaderConfiguration;
      }
      else
      {
        throw new InvalidOperationException(
          "An error occured trying to fetch a ListBoxContainerConfigurationBase instance for the specified configuration type " + configurationType + "." );
      }

      return containerConfiguration;
    }

    #endregion Internal Methods


    #region ContainerConfigurationsInvalidated Event

    internal event EventHandler<ConfigurationChangedEventArgs> ContainerConfigurationsInvalidated;

    #endregion ContainerConfigurationsInvalidated Event

    #region IWeakEventListener Members

    bool IWeakEventListener.ReceiveWeakEvent( Type managerType, object sender, EventArgs e )
    {
      bool handled = false;

      if( ( managerType == typeof( ContentTemplateChangedManager ) )
        || ( managerType == typeof( ItemContainerStyleChangedManager ) ) )
      {
        handled = true;

        ListBoxContainerConfigurationBase configuration = ( ListBoxContainerConfigurationBase )sender;
        this.Invalidate( configuration.ConfigurationType );
      }

      return handled;
    }

    #endregion
  }
}
